Like our mushy C-cut example above, even here you will see there are different styles. Sometimes the terrain is so mushy you can practically just gloop your tree plug into the ground without a shovel. [I was once on such a contract and it was great fun. I was planting the piece together with two good blokes, there were large fauna-like plants, we dropped some acid and planted while Jane’s Addiction blasted from my portable unit hitched to my planting bag straps using velcro I glued and sowed on.] Other times the checker can be extremely anal about absolutely straight plugs, in which case I’ve found it useful to slide the plug down into the hole ALONG the back of the blade, lift the blade a notch near the end, then reinsert the blade the same notch, in the process guiding the plug in the rest of the way so that it is not scrunched and twisted at the bottom.
If you make a wedge and line your plug along the left hand side of it, be careful not to create an unacceptable j-root (one that bends slightly at the very bottom – depends again on the contract specs). Remember that your blade is curved at the bottom. The C-cut is supposed to take care of this. Otherwise, I usually poke the tip of the root with my longest, middle finger before pulling out my hand, to take care of this potential problem.
Other planters like to cup their fingers around the root and slide it down the middle of the back of the blade, but for this I find you need to make a larger wedge.